Vinyl ester resins are known for their excellent corrosion resistance and physical strength. They are used when reacted with unsaturated monomers, in the manufacture of boats, windmill blades, chemical resistant storage tanks and pipes as well as ducting to handle chemical fumes. Liquid thermosettable vinyl ester resins are known to have a limited shelf life. Typically they must be stored in temperature controlled environments at 25.degree. C. (77.degree. F.) and must be used up within 3 to 6 months or they will polymerize into a solid in their containers and become unusable. Past efforts have focused on the use of inhibitor additives to improve shelf life without adversely affecting the catalyzed gel times of the vinyl ester. Typical shelf life enhancing inhibitors include phenothiazine (U.S. Pat. No. 3,683,045), copper naphthenate (JP 53,111,397), and certain imidizole compounds (U.S. Pat. No. 5,034,437, EP 436,921 and JP 3,103,446). Other shelf life enhancing inhibitors include certain hydroxylamines (U.S. Pat. No. 3,408,442), oxalic acid (U.S. Pat. No. 4,407,991), maleic anhydride (JP 1,240,509), and certain chlorinated nitrophenol compounds (U.S. Pat. No. 4,413,105).